Nail



8, 1933. v R. J. FARRELL 1,921,514

NAIL

Filed Sept. 5, 1931 I 15 ,15 L le 11 11 I lllllll 4' 14 IT 14 j [5 v J W Q g X W i T v jg .5.

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25 J 5 F g4 g 12% wrz m dam Patented Aug. 8, 1933 UNITE STATES LQZLSM PATENT This invention relates to nails and in particular, to nails which will not split the wood into which they are driven, and which will have the maximum holding power.

In order to prevent wood from splitting when a nail is being driven therethrough, it is essential that the entering end of the nail cuts or severs the wood fibres instead of spreading and wedging them apart. It is also essential that all portions of the body of the nail must be gripped by the wood in order to secure the'maximum holding power. It is well known in the art that the ordinary and commonly used nail having any shape of pointed end will split a board into which it is driven unless a great amount of care is used in selecting the place to start the nail and also the direction in which the nail is driven. This is due to the fact that the fibres of a piece of wood run lengthwise of the board and a nail with any kind of a pointed end spreads these fibres and wedges them apart, causing the board to split. Even in cases where the pointed end of the nail does not split the board, the fibres are spread apart on two sides of the nail and void or non-gripping areas result which materially reduces the holding power of the nail.

' Many different types of nails have been designed heretofore for reducing the splitting of the wood and increasing the holding power, but none of these types known to me has proven entirely satisfactory. To my knowledge the most successful of these types of nails has been one having a blunt triangular entering end, the size of the triangle being proportional to the size of the body of the nail and is inscribed in a circle corresponding to a section of the body of the nail. This type of nail punches a triangular shaped hole and, while it has reduced splitting to some extent, it has not proven wholly satisfactory since the points of the triangular end spread the fibres of the wood apart when it is being driven into a board, and as a result, void or non-gripping spaces are formed around the circumference ofthe body portion. That is, the points of the triangle spread the wood fibres at three points and prevent the wood from grippingthe body of the nail at those points,

' thereby materially reducing the holding power of the nail.

It is an object of this invention to provide a wire nail having a blunt entering end concentric to a section of the body of the nail which will positively cut the wood fibres and prevent splitting of the board or wood into which it is driven.

Another object of this invention is to provide a wire nail which will have the maximum holding power when driven into a piece of wood, board, or the like.

Another object is to provide a wire nail having a concave surface on the entering end thereof concentric to the longitudinal axis of the nail and of smaller area than the area of a section through the body portion of the nail.

A further object is to provide a wire nail which will cut the wood fibres, eliminate void spaces adjacent the body of the nail and will drive straight.

A still further object is to provide a nail which will be easy to manufacture and cheap in cost.

These and other objects which will be made readily apparent to those skilled in this particular 7 art are obtained by means of this invention, one

embodiment of which is described in the following specification and illustrated in the accompanying drawing, wherein;

Figure 1 is a view in side elevation of a nail embodying my invention.

Fig. 2 is an end view taken along the line IIII of Figure l.

Fig. 3 is a view taken through a piece of wood in which my improved nail has been driven and then partially withdrawn.

Fig. 4 is a view in side elevation ofv a nail embodying a modification of my invention, and

Fig. 5 is an end view of the nail shown in Fi 4. i

Referring to the drawing in detail, 10 designates a wire nail having a head portion 11, a body portion 12 of substantially circular crosssection, and'a uniformly tapering entering end 13 of circular section. In orderthatthe nail 10 will out rather than spread the fibres of wood or the like into which it is driven, the entering end 13 is hollowed out forming a concave surface 14 on the end of the nail and a closed annular cutting or knife-edge 15 which is concentric to the axis of the body of the nail. In order that the nail will be firmly gripped by the wood when the same is driven thereinto, the area of the annular cutting edge 15 on the entering end of the nail is smaller than the area of a section through the body portion of the nail.

As is readily apparent from Figure 3, when the nail 10 is driven into a piece of wood 16, the

' cutting or knife-edge 15 on the concaved surface 14 positively cuts or severs the fibres of the sponds to the diameter of the annular cutting edge 15 of the nail and since the area of the cutting edge is smaller than the area of a section taken through the body portion of the nail, it is readily seen that as the body of the nail enters the passage 17, the wood fibres will be compressed and caused to firmly grip all portions of the surface of the nail, and since none of the fibres are spread apart the greatest holding power possible is attained by my improved nail.

In Figure 4 I have shown a nail embodying a modification of my invention. In this modification, as in the previous embodiment of my invention, the nail 20 is provided with the customary driving head 21, body portion 22 which is of substantially uniform cross-section, and a tapering entering end 23. The body portion 22 may taper gradually from the head 21 to the entering end if desired. In this modification the end of the nail is not concaved andthe entering end terminates in a flat circular surface 24 which is concentric to the longitudinal axis of the nail and of smaller area than the area of a section through the body portion of the nail. The edge 25 of the circular end forms the cutting or lmife-edge.

In making my improved nail I prefer to form the same from drawn wire stock. The head is formed in suitable dies and the wire'is then cut or sheared to the, desired length. After the shearing operation I roll the blank about its 1ongitudinal axis while the end is gripped by members having their opposed faces inclined one to the other to form the concaved entering end.

It is readily apparent from the foregoing de-' scription that I have designed a nail which will readily cut the wood fibres and prevent the board from splitting and which is firmly gripped by the wood throughout its length, thereby giving the maximum holding power which can be obtained by any form of nail. I

It is to be understood that, while I have described a nail having a uniform cylindrical body portion and a circular entering end of smaller diameter than the diameter of the body portion of the nail, any desired shape of body portion and entering end may be employed without departing from this invention.

It is also to be understood that various other changes and modifications may be made without departing from the spirit of this invention and the scope of the appended claims. I

What I claim as new and desire to secure by Letters Patent is:

l. A non-splitting nail comprising a head and a shank having a tapered driving end, the surface metal of said shank adjacent the driving end being projected beyond the end of the shank to I provide an annular cutting edge of smaller diameter than the diameter of the body of the nail.

2. A- nail comprising a head and a shank having its lower end tapered and terminating in a ROBERT J. FARREIL. 

